A Prospective Randomized Comparative Study of Three Guided Bronchoscopic Approaches for Investigating Pulmonary Nodules

Background

The capability of bronchoscopy in the diagnosis of peripheral pulmonary nodules (PPNs) remains limited. Despite decades of effort, evidence suggests that the diagnostic accuracy for electromagnetic navigational bronchoscopy (EMN) and radial endobronchial ultrasound (EBUS) approach only 50%. New developments in robotic bronchoscopy (RB) may offer improvements in the assessment of PPNs.

Methods

A prospective single-blinded randomized controlled comparative study to assess success in localization and puncture of PPNs, using an ultrathin bronchoscope with radial EBUS (UTB-rEBUS) vs EMN vs RB in a human cadaver model of PPNs < 2 cm, was performed. The primary end point was the ability to successfully localize and puncture the target nodule, verified by cone-beam CT comparing RB and EMN. Secondary end points included needle to target position "miss" distance, and UTB-rEBUS comparisons.

Results

Sixty procedures were performed to target 20 PPNs over the study period. Implanted PPNs were distributed across all lobes, with 80% located within the lung periphery. The target PPN mean diameter was 16.5 ± 1.5 mm, with 50% noted to have a CT bronchus sign. The rate of successful PPN localization and puncture was superior when using RB, compared with EMN (80% vs 45%; P = .02). Among unsuccessful needle passes, the median needle to target "miss" distance was significantly different when comparing UTB-rEBUS, EMN, and RB (P = .0014).

Conclusions

In a cadaver model, use of RB significantly increased the ability to localize and successfully puncture small PPNs when compared with existing technologies. This study demonstrates the potential of RB to precisely reach, localize, and puncture small nodules in the periphery of the lung.